Field of the Invention
The present invention relates to wireless communication and, more particularly, to a MBMS operation method performed by a UE in a wireless communication system and the UE using the method.
Related Art
Standardization works of international mobile telecommunication (IMT)-advanced which is a next generation (i.e., post 3rd generation) mobile communication system are carried out in the international telecommunication union radio communication sector (ITU-R). The IMT-advanced aims at support of an Internet protocol (IP)-based multimedia service with a data transfer rate of 1 Gbps in a stationary or slowly moving state or 100 Mbps in a fast moving state.
3rd generation partnership project (3GPP) prepares LTE-Advanced (LTE-A) which is an improved version of long term evolution (LTE) based on orthogonal frequency division multiple access (OFDMA)/single carrier-frequency division multiple access (SC-FDMA) transmission as a system standard satisfying requirements of the IMT-advanced. The LTE-A is one of promising candidates for the IMT-advanced.
Multimedia Broadcast/Multicast Service (MBMS) is a service for simultaneously transmitting data packets to a plurality of users, similar to existing CBS (Cell Broadcast Service). However, the CBS is a low-speed message-based service, but MBMS is aimed at high-speed multimedia data transmission. Also, there is a difference that CBS is not based on IP (internet protocol) but MBMS is based on the IP multicast. According to the MBMS, when a certain level of users exist in the same cell, since users may receive the same multimedia data using a shared resource (or channel), the efficiency of radio resources is increased, and thus users may use the multimedia service cheaply.
The MBMS uses a common channel in order to allow a plurality of terminals to efficiently receive data for one service. For one service data, the base station allocates only one common channel without allocating a dedicated channel as many as the number of terminals desiring to receive the service in one cell. Since a plurality of terminals simultaneously receives the common channel, efficiency of radio resources is increased. With respect to the MBMS, the UE may receive the MBMS after receiving system information for the corresponding cell.